Relict of Meso-Archean paleosol developed on the komatiites from Koikary Area, Central Karelia

Abstract

A mineralogical and geochemical study was carried out to investigate the relict of Meso-Archean paleosol developed on the komatiites from Koikary Area, Central Karelia. The obtained data showed that the paleosol had the age of 3000–2930 million years and was not derived. Hugh values of CIA (91) and Al2O3/SiO2 (0.73) parameters indicate the high extent of chemical weathering. The evolution of the komatiite composition during weathering and the manner of REE distribution correspond to the paleosol formation during the oxic weathering in subaerial conditions of humid and warm climate with oxic. Refs 47. Figs 6. Tables 1.